SAFE-T-STAIN - SILICON DOPING STAINS

NEWS: We are able to source all the Safe-T-Stains again from Philtec. 

The Safe-T-Stain consists primarily of metal salts, in an electrolyte which have been used extensively to stain the more n-type regions on the silicon wafer. This characteristic holds consistent with the p on p+ being darkened. Repeatable results are achieved by control of light intensity and staining time. Five compositions are available to permit selection of the most appropriate stain.

Overstained regions often require no refinishing; they are merely wiped with a dampener paper towel and re-stained. The chemical composition of this stain does not necessitate extraordinary safety precautions during it's use. Minimal experience and technique are needed to stain junctions with Philtec Safe-T-Stain, because a unique stain composition is available for most junction impurity concentration ranges.

DSS-1 Solution colour Yellow

Formulated to be used on material which has heavily doped n & p layers. This stain has the least amount of activator and salts in it, making possible gradual delineation, and avoiding overstaining.  

DSS-2 Solution colour Red

For heavily doped layer with somewhat lighter doping of opposite polarity.

DSS-3 Solution colour Orange  

This stain has a strength of activator and salts that suits a wide range of applications.

DSS-4 Solution colour Green

Contains more activator, which is useful for materials, where other stains would be to slow to bring out the layers. 

DSS-5 Solution colour Blue

Has the strongest concentration of activator & salts, for use on very lightly doped areas.

Note: For applications where wafers will be going through further diffusions, the stain can be removed by using Ammonium Persulfate (NH4) S2O2.

Features :-

• Enables observation of the staining through a microscope, whilst it is taking place, without damaging the optics.

• Sharply and rapidly delineates diffused abd epitaxial layers in material with a wide variety of deposits, concentrations, and layer depths.

• Does not etch out layers to be measured, most noticeable when measuring thin layers.

• Minimally effects oxide on the surface of a wafer when it is present.

• Eliminates the need for a fume hood, and does not corrode the surrounding equipment.